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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 | // SPDX-License-Identifier: GPL-2.0-or-later /* * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) */ #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/sockios.h> #include <linux/spinlock.h> #include <linux/net.h> #include <linux/gfp.h> #include <net/ax25.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <net/sock.h> #include <linux/uaccess.h> #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> void ax25_ds_nr_error_recovery(ax25_cb *ax25) { ax25_ds_establish_data_link(ax25); } /* * dl1bke 960114: transmit I frames on DAMA poll */ void ax25_ds_enquiry_response(ax25_cb *ax25) { ax25_cb *ax25o; /* Please note that neither DK4EG's nor DG2FEF's * DAMA spec mention the following behaviour as seen * with TheFirmware: * * DB0ACH->DL1BKE <RR C P R0> [DAMA] * DL1BKE->DB0ACH <I NR=0 NS=0> * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> * DL1BKE->DB0ACH <RR R F R0> * * The Flexnet DAMA Master implementation apparently * insists on the "proper" AX.25 behaviour: * * DB0ACH->DL1BKE <RR C P R0> [DAMA] * DL1BKE->DB0ACH <RR R F R0> * DL1BKE->DB0ACH <I NR=0 NS=0> * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> * * Flexnet refuses to send us *any* I frame if we send * a REJ in case AX25_COND_REJECT is set. It is superfluous in * this mode anyway (a RR or RNR invokes the retransmission). * Is this a Flexnet bug? */ ax25_std_enquiry_response(ax25); if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) { ax25_requeue_frames(ax25); ax25_kick(ax25); } if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL) ax25_ds_t1_timeout(ax25); else ax25->n2count = 0; ax25_start_t3timer(ax25); ax25_ds_set_timer(ax25->ax25_dev); spin_lock(&ax25_list_lock); ax25_for_each(ax25o, &ax25_list) { if (ax25o == ax25) continue; if (ax25o->ax25_dev != ax25->ax25_dev) continue; if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) { ax25_ds_t1_timeout(ax25o); continue; } if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) { ax25_requeue_frames(ax25o); ax25_kick(ax25o); } if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL) ax25_ds_t1_timeout(ax25o); /* do not start T3 for listening sockets (tnx DD8NE) */ if (ax25o->state != AX25_STATE_0) ax25_start_t3timer(ax25o); } spin_unlock(&ax25_list_lock); } void ax25_ds_establish_data_link(ax25_cb *ax25) { ax25->condition &= AX25_COND_DAMA_MODE; ax25->n2count = 0; ax25_calculate_t1(ax25); ax25_start_t1timer(ax25); ax25_stop_t2timer(ax25); ax25_start_t3timer(ax25); } /* * :::FIXME::: * This is a kludge. Not all drivers recognize kiss commands. * We need a driver level request to switch duplex mode, that does * either SCC changing, PI config or KISS as required. Currently * this request isn't reliable. */ static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param) { struct sk_buff *skb; unsigned char *p; if (ax25_dev->dev == NULL) return; if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL) return; skb_reset_network_header(skb); p = skb_put(skb, 2); *p++ = cmd; *p++ = param; skb->protocol = ax25_type_trans(skb, ax25_dev->dev); dev_queue_xmit(skb); } /* * A nasty problem arises if we count the number of DAMA connections * wrong, especially when connections on the device already existed * and our network node (or the sysop) decides to turn on DAMA Master * mode. We thus flag the 'real' slave connections with * ax25->dama_slave=1 and look on every disconnect if still slave * connections exist. */ static int ax25_check_dama_slave(ax25_dev *ax25_dev) { ax25_cb *ax25; int res = 0; spin_lock(&ax25_list_lock); ax25_for_each(ax25, &ax25_list) if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) { res = 1; break; } spin_unlock(&ax25_list_lock); return res; } static void ax25_dev_dama_on(ax25_dev *ax25_dev) { if (ax25_dev == NULL) return; if (ax25_dev->dama.slave == 0) ax25_kiss_cmd(ax25_dev, 5, 1); ax25_dev->dama.slave = 1; ax25_ds_set_timer(ax25_dev); } void ax25_dev_dama_off(ax25_dev *ax25_dev) { if (ax25_dev == NULL) return; if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) { ax25_kiss_cmd(ax25_dev, 5, 0); ax25_dev->dama.slave = 0; ax25_ds_del_timer(ax25_dev); } } void ax25_dama_on(ax25_cb *ax25) { ax25_dev_dama_on(ax25->ax25_dev); ax25->condition |= AX25_COND_DAMA_MODE; } void ax25_dama_off(ax25_cb *ax25) { ax25->condition &= ~AX25_COND_DAMA_MODE; ax25_dev_dama_off(ax25->ax25_dev); } |